Our community of investigators seeks renewed support for a pre- and post-doctoral training program that addresses the role of microbes in health and disease at the University of Wisconsin-Madison. Microbiology is fundamentally important to human health due to the prevalence and consequences of infectious diseases. Its significance has been elevated by bioterrorism and discoveries of the unforeseen roles for microbes in certain human maladies and in promoting normal human physiology and health. The proposed Microbes in Health and Disease (MHD) training program represents the natural and synergistic synthesis of the broad disciplines microbial pathogenesis, beneficial microbiology, and host responses. MHD will have its physical and intellectual home in a state-of-the-art new Microbial Sciences Building where basic and clinical scientists interact and collaborate, providing a strong sense of place, cohesion and identity to the Training Program. Our pre-doctoral trainees are drawn chiefly from the Microbiology Doctoral Training Program (MDTP), a highly ranked graduate program. Our post-doctoral fellows are drawn chiefly from a strong pool of PhD and Infectious Disease MD fellows, the latter from a program with a long history of placing fellows into academic medicine. MHD trainees and faculty trainers hold program-wide bi-weekly meetings together, host invited speakers, and have a website and list serve. Medical Microbiology and Immunology, Bacteriology, Internal Medicine, and Pediatrics are core departments of MHD and MDTP activities, and offer required didactic, journal club and seminar courses to our trainees. Instruction is provided in host-microbe interactions, microbial pathogenesis, immunology, infectious disease, translational medicine, and the responsible conduct of research. Our 31 faculty trainers span 9 departments in 4 colleges and actively collaborate with each other in both research and teaching. All faculty trainers are productive scientists with proven NIH or equivalent funding records and strong records of graduate training. Most are tenured (20 full, 7 associate professors) and 4 promising junior faculty trainers will be mentored by senior training faculty. The training program faculty are dedicated to recruiting outstanding students and fellows, including focused efforts for minority candidates, and are committed to pre- and post-doctoral mentoring and didactic and research training. To support this commitment, and the NIH- stated need to train scientists in the area of microbes in health and disease, support is requested for 8 trainees annually: 5 predoctoral trainees, and 3 postdoctoral trainees, including two MD and one PhD fellows. Each trainee is mentored by a committee consisting of a thesis advisor or mentor and 4 other faculty, and all trainees are also co-mentored by virtue of joint trainer service on these committees. The program and its trainers are highly regarded in the scientific community, and fill a unique niche on campus and a critical national need. The success of the program in the past cycle is evidenced by 86 collective publications among the 15 trainees, and their progress into competitive postdoctoral positions or academic, industry or government research careers.